loop0: detected capacity change from 0 to 32768
BTRFS: device fsid 395ef67a-297e-477c-816d-cd80a5b93e5d devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5321)
BTRFS info (device loop0): first mount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d
BTRFS info (device loop0): using sha256 (sha256-lib) checksum algorithm
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): turning on async discard
BTRFS info (device loop0): enabling free space tree
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5321 at arch/x86/kvm/../../../virt/kvm/pfncache.c:267 __kvm_gpc_refresh+0x1187/0x1310 virt/kvm/pfncache.c:267
Modules linked in:
CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__kvm_gpc_refresh+0x1187/0x1310 virt/kvm/pfncache.c:267
Code: c6 05 64 4b 27 0e 01 48 c7 c7 74 e1 6f 8d be 35 04 00 00 48 c7 c2 40 ea 61 8b e8 c4 ce 5d 00 e9 fe f1 ff ff e8 8a 65 80 00 90 <0f> 0b 90 bb ea ff ff ff e9 7e fe ff ff e8 77 65 80 00 90 0f 0b 90
RSP: 0018:ffffc9000fe07340 EFLAGS: 00010283
RAX: ffffffff813fadd6 RBX: ffff888000000000 RCX: 0000000000100000
RDX: ffffc9000dd2a000 RSI: 0000000000000b7f RDI: 0000000000000b80
RBP: ffffc9000fe074c8 R08: ffffffff8f7d0f77 R09: 1ffffffff1efa1ee
R10: dffffc0000000000 R11: fffffbfff1efa1ef R12: ffff8880006653e0
R13: dffffc0000000000 R14: ffff888000000000 R15: ffffffffffffff01
FS:  00007f56392786c0(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055da002c9938 CR3: 000000001c153000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 kvm_gpc_refresh+0xe1/0x140 virt/kvm/pfncache.c:382
 kvm_xen_set_evtchn+0x164/0x230 arch/x86/kvm/xen.c:1943
 kvm_xen_inject_timer_irqs+0xfd/0x200 arch/x86/kvm/xen.c:118
 vcpu_run+0xc2c/0x7040 arch/x86/kvm/x86.c:11624
 kvm_arch_vcpu_ioctl_run+0x116c/0x1cb0 arch/x86/kvm/x86.c:11956
 kvm_vcpu_ioctl+0x95c/0xe90 virt/kvm/kvm_main.c:4476
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f563838f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5639278038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f56385e5fa0 RCX: 00007f563838f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 000000000000000a
RBP: 00007f5638413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f56385e6038 R14: 00007f56385e5fa0 R15: 00007ffe98b1b2b8
 </TASK>